This invention relates generally to fluid pumping apparatus and more particularly to a portable groundwater sampling unit for use in water quality control.
In recent years, federal, state and local environmental regulations have been imposed to require the monitoring of groundwater quality. Among the requirements of these regulations is that monitoring wells be installed in the vicinity of regulated groundwater supply facilities. Because the design and construction of sampling wells differs significantly from that of supply wells, new technology has been required to provide accurate, efficient, and consistent testing of water samples.
The early equipment developed for groundwater sampling had many inadequacies. Much of the equipment was quite expensive, complicated to operate, and impractical for use in remote locations. Also, sampling results were negatively effected by improper handling and field cleaning of the equipment, as well as inconsistent well depth sampling. Further, most of the equipment was so heavy and bulky that it was impractical to attempt to transport it from site to site. As a result, installations were made usually at each testing site which further increased the cost of testing.
As the number of regulated sites and testing programs expanded, it became apparent that the development of practical and effective portable sampling equipment was a necessity. At present the number of portable sampling units are available on the market. These units typically include a pneumatically or electrically operated sampling pump and a service hose which provides pneumatic or electric power to the pump and a conduit for carrying water samples to the surface. They also include a storage reel and a frame or stand on which the reel is mounted. As a group, however, these units continue to exhibit many of the deficiencies found in early sampling equipment. Many are too large or heavy to be easily transported or operated by one person. For example, some units require, when recovering the pump from the sampling well, that the operator hold the unit above the wellhead with one hand and attempt to operate the reel with the other in order to avoid scuffing the service cable on the upper edge of the wellhead. Also, many of them employ a service cable which is inherently difficult to clean in the field or which permits incursion of well water into the cable, thereby increasing the likelihood of cross contamination between wells.
Accordingly, it is an object of this invention to provide for an improved portable groundwater sampling unit which is easily transportable and operable by a single operator.
Particularly, it is an object of this invention to provide for a sampling unit which can be suspended from a conventional wellhead in such a manner and position that the service hose is guided directly from the storage reel to the well casing, thus reducing the possibility of damage to it during operation and eliminating the necessity of the operators holding the reel assembly during pump retrieval operations.
Another object of this invention to provide for improved service hose for a portable groundwater sampling unit which functions as a unitary cable when being wound on a reel and which is sealed to prevent leakage of well water into the hose.